Add locking to the various iicbus(4) bridge drivers:

- Just grab Giant in the ixp425_iic(4) driver since this driver uses
  a shared address/data register window pair to access the actual
  I2C registers.  None of the other ixp425 drivers lock access to these
  shared address/data registers yet and that would need to be done before
  this could use any meaningful locking.
- Add locking to the interrupt handler and 'iicbus_reset' methods of the
  at91_twi(4) driver.
- Add locking to the pcf(4) driver.  Other pcf(4) fixes include:
  - Don't needlessly zero the softc.
  - Use bus_foo rather than bus_space_foo and remove bus space tag and
    handle from softc.
- The lpbb(4) driver just grabs Giant for now.  This will be refined later
  when ppbus(4) is locked.
- As was done with smbus earlier, move the DRIVER_MODULE() lines to match
  the bus driver (either iicbus or iicbb) to the bridge driver into the
  bridge drivers.

Tested by:	sam (arm/ixp425)

2 files changed, 16 insertions, 0 deletions

diff --git a/sys/arm/at91/at91_twi.c b/sys/arm/at91/at91_twi.c
index 0d8a2d4..ec05d14 100644
--- a/sys/arm/at91/at91_twi.c
+++ b/sys/arm/at91/at91_twi.c
@@ -155,6 +155,8 @@ at91_twi_detach(device_t dev)
 	if (sc->iicbus && (rv = device_delete_child(dev, sc->iicbus)) != 0)
 		return (rv);
 
+	AT91_TWI_LOCK_DESTROY(sc);
+
 	return (0);
 }
 
@@ -211,6 +213,7 @@ at91_twi_intr(void *xsc)
 	status = RD4(sc, TWI_SR);
 	if (status == 0)
 		return;
+	AT91_TWI_LOCK(sc);
 	sc->flags |= status & (TWI_SR_OVRE | TWI_SR_UNRE | TWI_SR_NACK);
 	if (status & TWI_SR_RXRDY)
 		sc->flags |= TWI_SR_RXRDY;
@@ -220,6 +223,7 @@ at91_twi_intr(void *xsc)
 		sc->flags |= TWI_SR_TXCOMP;
 	WR4(sc, TWI_IDR, status);
 	wakeup(sc);
+	AT91_TWI_UNLOCK(sc);
 	return;
 }
 
@@ -230,6 +234,7 @@ at91_twi_wait(struct at91_twi_softc *sc, uint32_t bit)
 	int counter = 100000;
 	uint32_t sr;
 
+	AT91_TWI_ASSERT_LOCKED(sc);
 	while (!((sr = RD4(sc, TWI_SR)) & bit) && counter-- > 0 &&
 	    !(sr & TWI_SR_NACK))
 		continue;
@@ -247,6 +252,7 @@ at91_twi_rst_card(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
 	int clk;
 
 	sc = device_get_softc(dev);
+	AT91_TWI_LOCK(sc);
 	if (oldaddr)
 		*oldaddr = sc->twi_addr;
 	sc->twi_addr = addr;
@@ -275,6 +281,7 @@ at91_twi_rst_card(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
 	WR4(sc, TWI_CR, TWI_CR_MSEN | TWI_CR_SVDIS);
 	WR4(sc, TWI_CWGR, sc->cwgr);
 	printf("setting cwgr to %#x\n", sc->cwgr);
+	AT91_TWI_UNLOCK(sc);
 
 	return 0;
 }
diff --git a/sys/arm/xscale/ixp425/ixp425_iic.c b/sys/arm/xscale/ixp425/ixp425_iic.c
index ecc889f..38a86a6 100644
--- a/sys/arm/xscale/ixp425/ixp425_iic.c
+++ b/sys/arm/xscale/ixp425/ixp425_iic.c
@@ -106,9 +106,11 @@ ixpiic_getscl(device_t dev)
 	struct ixpiic_softc *sc = ixpiic_sc;
 	uint32_t reg;
 
+	mtx_lock(&Giant);
 	GPIO_CONF_SET(sc, IXP425_GPIO_GPOER, GPIO_I2C_SCL_BIT);
 
 	reg = GPIO_CONF_READ_4(sc, IXP425_GPIO_GPINR);
+	mtx_unlock(&Giant);
 	return (reg & GPIO_I2C_SCL_BIT);
 }
 
@@ -118,9 +120,11 @@ ixpiic_getsda(device_t dev)
 	struct ixpiic_softc *sc = ixpiic_sc;
 	uint32_t reg;
 
+	mtx_lock(&Giant);
 	GPIO_CONF_SET(sc, IXP425_GPIO_GPOER, GPIO_I2C_SDA_BIT);
 
 	reg = GPIO_CONF_READ_4(sc, IXP425_GPIO_GPINR);
+	mtx_unlock(&Giant);
 	return (reg & GPIO_I2C_SDA_BIT);
 }
 
@@ -129,11 +133,13 @@ ixpiic_setsda(device_t dev, char val)
 {
 	struct ixpiic_softc *sc = ixpiic_sc;
 
+	mtx_lock(&Giant);
 	GPIO_CONF_CLR(sc, IXP425_GPIO_GPOUTR, GPIO_I2C_SDA_BIT);
 	if (val)
 		GPIO_CONF_SET(sc, IXP425_GPIO_GPOER, GPIO_I2C_SDA_BIT);
 	else
 		GPIO_CONF_CLR(sc, IXP425_GPIO_GPOER, GPIO_I2C_SDA_BIT);
+	mtx_unlock(&Giant);
 	DELAY(I2C_DELAY);
 }
 
@@ -142,11 +148,13 @@ ixpiic_setscl(device_t dev, char val)
 {
 	struct ixpiic_softc *sc = ixpiic_sc;
 
+	mtx_lock(&Giant);
 	GPIO_CONF_CLR(sc, IXP425_GPIO_GPOUTR, GPIO_I2C_SCL_BIT);
 	if (val)
 		GPIO_CONF_SET(sc, IXP425_GPIO_GPOER, GPIO_I2C_SCL_BIT);
 	else
 		GPIO_CONF_CLR(sc, IXP425_GPIO_GPOER, GPIO_I2C_SCL_BIT);
+	mtx_unlock(&Giant);
 	DELAY(I2C_DELAY);
 }
 
@@ -184,3 +192,4 @@ static driver_t ixpiic_driver = {
 static devclass_t ixpiic_devclass;
 
 DRIVER_MODULE(ixpiic, ixp, ixpiic_driver, ixpiic_devclass, 0, 0);
+DRIVER_MODULE(iicbb, ixpiic, iicbb_driver, iicbb_devclass, 0, 0);